Lifetime Of Facilities Research Articles

Comparing the net-energy balance of standalone photovoltaic-coupled electrolysis and photoelectrochemical hydrogen production.

Photovoltaic-coupled electrolysis (PV-E) and photoelectrochemical (PEC) water splitting are two options for storing solar energy as hydrogen. Understanding the requirements for achieving a positive energy balance over the lifetime of facilities using these technologies is important for ensuring sustainability. While neither technology has yet reached full commercialisation, they are also at very different technology readiness levels and scales of development. Here, we model the energy balance of standalone large-scale facilities to evaluate their energy return on energy invested (ERoEI) over time and energy payback time (EPBT). We find that for average input parameters based on present commercialised modules, a PV-E facility shows an EPBT of 6.2 years and ERoEI after 20 years of 2.1, which rises to approximately 3.7 with an EPBT of 2.7 years for favourable parameters using the best metrics amongst large-scale modules. The energy balance of PV-E facilities is influenced most strongly by the upfront embodied energy costs of the photovoltaic component. In contrast, the simulated ERoEI for a PEC facility made with earth abundant materials only peaks at 0.42 after 11 years and about 0.71 after 20 years for facilities with higher-performance active materials. Doubling the conversion efficiency to 10% and halving the degradation rate to 2% for a 10-year device lifetime can allow PEC facilities to achieve an ERoEI after 20 years of 2.1 for optimistic future parameters. We also estimate that recycling the materials used in hydrogen production technologies improves the energy balance by 28% and 14% for favourable-case PV-E and PEC water splitting facilities, respectively.

Formulations for automatic optimization of decommissioning timing in offshore oil and gas field development planning

A mathematical programming formulation has been developed to optimize the drilling program, the production allocation, and the decommissioning time in early-stage field development planning. Various abandonment constraints are considered in the optimization model when searching for the best decommissioning time for the long-term field development strategy. The model is tested on a real field development planning consisting of two reservoirs produced with subsea wells to an offshore facility. The novelty of this work is the utilization of mathematical programming to formulate and solve early-stage field development planning considering the variable decommissioning time. The results show that considering a variable decommissioning time in early-stage field development planning yields improved economic margins. Further, it provides operators a decision-support tool with enhanced capabilities of forecasting the best decommissioning time, improving the forecasts for processing and production planning, expected revenue and lifetime of facilities, and anticipating and preparing for field abandonment in advance. The optimization model is capable of determining the drilling and production schedules, and the optimal decommissioning time that yielded the maximum net present value for the project.

데이터 기반 지상용 변압기의 잔여수명과 고장확률(PoF) 도출방안 연구

In Korea, as power facilities are aging like overseas nations, maintenance and replacement costs of power facilities are expected to increase rapidly. In order to operate power facilities with a limited budget efficiently, it is necessary to introduce Asset Management System (AMS) in maintenance of the power facility in line with the global trend. To this end, it is essential for power companies to predict the remaining lifetime of power facilities and develop Probability of Failure (PoF) in their own way depending on the type and operating conditions of power facilities. Existing studies only calculated the statistical life expectancy of the power facility, but in this study, both of the statistical life expectancy and the condition remaining lifetime are presented in order to assess the PoF of power facility, in which the statistical life expectancy is calculated by using Weibull distributions. In this study, we present the criteria for determining the condition remaining lifetime using Health Index, inspection and diagnosis data of the pad mounted transformer operated by Korea Electric Power Corporation (KEPCO) in the field. In addition, the final remaining lifetime of the pad mounted transformer was derived through the folding function and was converted into PoF using Hazard rate distribution based on the apparent age. PoF derived in this study is expected to be used in the risk matrix of the AMS and useful in establishing the systematic maintenance plan of the pad mounted transformer.

Holding Geostationary Satellite at Given Standing Point, Taking into Account Additional Phase Restrictions

The active lifetime of orbital facilities in the geostationary orbit (GSO), which include stationary artificial earth satellites (SAES) for various purposes, can be more than 15 years. At the same time, in modern conditions of orbital grouping increment, the number of space debris, including those on the GSO, also increases: SAES, which have finished its active lifetime and were not transferred to disposal orbit for some reasons, shards of SAES appeared from collision with meteors or accidents. This leads to the increase of probability of collisions with active SAESs. The listed factors determine the need of considering not only the problem of keeping SAESs in vicinities of position, but also the task of avoiding collisions with space debris objects (SDO), while the costs of the working fluid should not increase.
 A great attention is being paid to rational power units placing during the projection of new space shuttles, especially those with long useful lifetime. In this article, it is assumed that SESs are equipped with several correction motors, which make it possible to create control accelerations in only several directions, without changing the orientation of the SES itself. In other words, in this task it is assumed that the corrections of the parameters of the AES orbit do not affect the orientation of the SAES itself. This condition is a severe limitation in the synthesis of the SES’s control system.
 In the considered methodological approach, the costs of the working fluid are set as a functionality from control, which are necessary to perform the next correction, after which the SAES will not have dangerous distances and approaching in projection horizon’s interval. This makes it possible to avoid situations when the decision on control is being made after the SES leaves the vicinity of the station point, and first of all, the approach to the SDO at a distance less than a liminal one. This article provides the results of modeling, which indicate the effectiveness of the proposed solutions.
 An important advantage compared with the existing methods is the consideration of the movement of the SAES relatively not only to the stationary point, but also to several other objects located in its vicinity, both controlled and uncontrolled. Moreover, there can be any given number of objects.

Research of Technology for Repair of Heat Exchangers of Nuclear Power Plants by Laser Welding

Extending the lifetime of energy facilities is extremely important today. This is especially true of nuclear power plants, the closure (or modernization) of which poses enormous financial and environmental problems. High-quality repair of reactors can significantly extend their service life. One of the critical parts is heat exchangers, the tubes of which quite often fail. Sealing, as a type of repair of heat exchanger tubes by the plugs, is promising provided that the joint quality is high. Practical experience in the use of welding to solve this problem has shown the need to search technological solutions associated with increasing the depth of penetration and reducing the area of thermal effect. The aim of the work was to develop a highly efficient technology for repair and extension of service life of heat exchangers of nuclear power plants based on the results of studying the technological features of laser welding of joints of dissimilar austenitic steels AISI 321 and AISI 316Ti in the vertical spatial position. Based on the results of the analysis of mechanical test data, visual and radiographic control, impermeability tests and metallographic studies of welded joints, the appropriate modes of laser welding of plugs have been determined. The principal causes of defects during laser welding of annular welded joints of dissimilar stainless steels are determined and techniques for their elimination and prevention of their formation are proposed. Based on the results of the research, technological recommendations for laser welding of plugs in the heat exchange tube of the collector are formulated, which significantly improves the technology of repair of steam generators of nuclear power plants and extends the service life of reactors.

An integrated FMEA and MCDA based risk management approach to support life extension of subsea facilities in high-pressure–high-temperature (HPHT) conditions

The majority of facilities installed in offshore oil and gas fields during the 1980s and 1990s were designed to operate in ‘normal’ conditions. However, during the operational life of the fields, some new high pressure/high temperature (HPHT) wells may be discovered and tied back to older facilities. Operating these facilities beyond their design parameters in harsh environments may lead to catastrophic failures, resulting in significant economic losses and environmental problems. Managing the risks associated with failure of ageing subsea facilities in HPHT environments is considered as a very complex and critical task. To overcome such challenge, there is a need for development of decision-making methods that are capable of estimating precisely the risks associated with HPHT conditions as well as prioritising the risk mitigation and remediation strategies. This paper aims to propose an integrated risk management framework – based on Failure Mode and Effects Analysis (FMEA) approach and a hybrid Multi-Criteria Decision Analysis (MCDA) model – for evaluating the risks and prioritising mitigation strategies over the extended lifetime of subsea facilities in HPHT environments. For the purpose of illustrating the model, a case study of subsea manifold and flowlines is provided and the results are evaluated and discussed. Our findings indicate that the proposed approach offers significant improvement to the classical risk management processes applied to subsea oil and gas facilities as it can assist asset managers, risk analyst, regulators and policy makers with a decision model which considers both subjective (qualitative) judgements and objective (quantitative) evaluation measures.

Data-driven predictive maintenance planning framework for MEP components based on BIM and IoT using machine learning algorithms

Facility managers usually conduct reactive maintenance or preventive maintenance strategies in building maintenance management. However, there are some limitations that reactive maintenance cannot prevent failure, and preventive maintenance cannot predict the future condition of MEP components and repair in advance to extend the lifetime of facilities. Therefore, this study aims to apply a predictive maintenance strategy with advanced technologies to overcome these limitations. Building information modeling (BIM) and Internet of Things (IoT) have the potential to improve the efficiency of facility maintenance management (FMM). Despite the significant efforts that have been made to apply BIM and IoT to the architecture, engineering, construction, and facility management (AEC/FM) industry, BIM and IoT integration for FMM is still at an initial stage. In order to provide a better maintenance strategy for building facilities, a data-driven predictive maintenance planning framework based on BIM and IoT technologies for FMM was developed, consisting of an information layer and an application layer. Data collection and data integration among the BIM models, FM system, and IoT network are undertaken in the information layer, while the application layer contains four modules to achieve predictive maintenance, namely: (1) condition monitoring and fault alarming module, (2) condition assessment module, (3) condition prediction module, and (4) maintenance planning module. Machine learning algorithms, ANN and SVM, are used to predict the future condition of MEP components. Furthermore, the developed framework was applied in an illustrative example to validate the feasibility of the approach. The results show that the constantly updated data obtained from the information layer together with the machine learning algorithms in the application layer can efficiently predict the future condition of MEP components for maintenance planning.

Life cycle greenhouse gas emissions of Chinese urban household consumption based on process life cycle assessment: Exploring the critical influencing factors

The household is an important sector for resource consumption and environmental impact. The consumption patterns and influencing factors of this sector must be identified to switch to a more sustainable stage of development. Process life cycle assessment (PLCA) can provide a bottom-up picture of greenhouse gas (GHG) emissions and is suitable for the development of consumer-induced carbon management measures. In this study, PLCA was used to determine GHG emissions from Chinese urban households and to explore the primary influencing factors of GHG. The results indicated that, in 2014, the average global warming potential (GWP) per Chinese urban household was 5.36 t CO2-eq. Residential consumption contributed 33.5% to the total GWP, followed by food and household facilities consumption. Scenario analysis indicated that changing the power grid, extending the lifespan of buildings, and reducing vehicle ownership could have significant effects on Chinese urban household GWP impact. Green consumption patterns were also determined, with electricity savings, reduction in the frequency of automobile use, and prolonging the lifetime of household facilities all decreasing the GWP of household consumption.

Sorting Line Modelling as an Integral Part of Complex Tools for Decision-making in Waste Management

This paper describes sorting line technology modelling as a potential key element of waste management at the municipal level, which, however, does not mean final treatment but only waste pre-treatment as an integral part of waste management chain. The outputs of the presented model are used as one of the key inputs to the NERUDA tool. The NERUDA tool provides support for strategic decision making in the field of waste management. The computational system of NERUDA has been created as an open tool and it is still being developed and expanded to suit current research tasks. The key part of NERUDA is a waste management related logistic problem. Hereafter, the NERUDA tool consists of a number of sub-modules and components that represent waste management technologies and procedures. Excessive separation not coupled with utilization of recyclables in the market can significantly disadvantage the overall economics of the chain. For the reason, a techno-economic model that can establish a representative waste treatment cost in order to obtain a valuable secondary raw material has been developed. Combination of techno-economic models allows to prepare unique, comprehensive and high-quality case studies. Various technological arrangements of sorting line, attainable rates of material separation and potential for subsequent energy recovery are considered. It is also appropriate to consider related costs of sorted waste collection, which may be a very economically demanding issue in overall waste processing balance. Positive selling price of secondary raw materials on the market is an assumption in addition to processing prices estimation. The model can serve as a useful tool for costs estimating (investment, profits). Furthermore, the model can serve as a key tool for feasibility studies in the context of sorting systems and the secondary raw material production over the lifetime of facilities. The practical contribution of described model is presented through a case study in the conditions of the Czech waste management.

A review of technology and policy deep decarbonization pathway options for making energy-intensive industry production consistent with the Paris Agreement

Abstract The production of commodities by energy-intensive industry is responsible for 1/3 of annual global greenhouse gas (GHG) emissions. The climate goal of the Paris Agreement, to hold the increase in the global average temperature to well below 2 °C above pre-industrial levels while pursuing efforts to limit the temperature increase to 1.5 °C, requires global GHG emissions reach net-zero and probably negative by 2055–2080. Given the average economic lifetime of industrial facilities is 20 years or more, this indicates all new investment must be net-zero emitting by 2035–2060 or be compensated by negative emissions to guarantee GHG-neutrality. We argue, based on a sample portfolio of emerging and near-commercial technologies for each sector (largely based on zero carbon electricity & heat sources, biomass and carbon capture, and catalogued in an accompanying database), that reducing energy-intensive industrial GHG emissions to Paris Agreement compatible levels may not only be technically possible, but can be achieved with sufficient prioritization and policy effort. We then review policy options to drive innovation and investment in these technologies. From this we synthesize a preliminary integrated strategy for a managed transition with minimum stranded assets, unemployment, and social trauma that recognizes the competitive and globally traded nature of commodity production. The strategy includes: an initial policy commitment followed by a national and sectoral stakeholder driven pathway process to build commitment and identify opportunities based on local zero carbon resources; penetration of near-commercial technologies through increasing valuation of GHG material intensity through GHG pricing or tradable performance based regulations with protection for competitiveness and against carbon leakage; research and demand support for the output of pilot plants, including some combination of guaranteed above-market prices that decline with output and an increasing requirement for low carbon inputs in government procurement; and finally, key supporting institutions.

Verification of the dependence of factors determining the market value of residential real estate at the stages of the life cycle

The paper reflects the results of the study of the dependence of factors that form the market value of residential real estate objects at the stages of life cycle on the example of the residential real estate market in the city of Krasnoyarsk. It was determined that the location and lifetime of facilities are the key factors in the formation of the market value of residential property. Based on the conducted economic and statistical analysis, it is proved that the importance of the residential object location can suppress the influence of a high degree of depreciation of the building, thereby increasing the market value of residential property in it. It is justified in the work that the value of a location, being a qualitative characteristic of residential real estate, involves the development of quantitative approaches to its measuring and valuating in order to solve theoretical and methodological problems of management and development of housing construction.

Modelling the material and energy costs of the transition to low-carbon energy

The evolution from 2000 to 2050 of the needs in concrete, steel, aluminium and copper to build the infrastructure of electricity generation is modelled for the scenarios of García-Olivares et al. (2012), Ecofys-WWF (2012) and the blue map scenario of the IEA (2010). A simple dynamic model is used to estimate the primary production, recycling and lost flows as well as the cumulative stocks of material to be produced, to go into the infrastructure and to be lost. The energy of material production is also estimated. When compared with the expected evolution of global material and energy demands, the modelling results suggest that i) the transition to low-carbon energies implies a substantial increase of raw materials and energy consumption, ii) the shorter lifetime of wind and solar facilities and the loss of recycling implies that the total amount of metal to be produced during the deployment of the infrastructure of energy is significantly higher than their amount stocked in the infrastructure, and iii) the needs in materials and energy will occur in a period of expected increase of primary metal consumption at the world scale and limited potential of recycling

RICA: A Tracked Robot for Sampling and Radiological Characterization in the Nuclear Field

Throughout the lifetime of nuclear facilities, radiological inspections are of vital importance, as controlling the radiological state of these facilities is necessary to ensure that their operations remain safe. These inspections are equally important during dismantling and decommissioning (D&D). Inspections of facilities that have contained radionuclides, particularly high activity cells, and very high activity cells are the first step when planning to carry out maintenance and D&D operations. Therefore, the development of investigation robots for hostile environments is a strategic approach in the nuclear field in order to meet these needs. The CEA and CYBERIA have worked together to develop the RICA robot (Robot d'Inspection pour Cellules Aveugles, or blind cell inspection robot), which can locate and measure the activity of radioactive sources. Since 2007, RICA is one of the strategic apparatuses that the CEA has been using for dismantling operations in its nuclear facilities. This small tracked robot was developed to offer a good level of modularity in terms of the onboard equipment able to carry out inspection and sampling missions in extremely hostile environments. To be able to do this, it can be operated either with a complete unit of radiological measurement tools or with a remote‐handling arm. The measurement unit consists of a gamma camera, a gamma spectrometer, and a dose rate detector. This innovative radiological measurement unit enables in situ activity quantification and the collection of all the information necessary to interpret the radiological spectra. On the other hand, when equipped with a remote‐handling arm, the unit can be used to carry out samplings, which will then be analyzed in a laboratory. This paper first presents the RICA robot, giving its main technical features. The innovative radiological measurement unit is described, explaining each of its bricks. The gamma irradiator tests that qualified the robot's functioning under irradiation are described, and the dose resistance results are analyzed. Lastly, examples of tasks in which RICA has been used in CEA nuclear facilities illustrate the robot's modularity.

Lifetime Distribution Model of Port Facilities with Pitting Corrosion of Stochastic Processes

Pitting corrosion damages seriously the structure strength of port facilities. To estimate the lifetime of port facilities, a new lifetime distribution model of port facilities with pitting corrosion of stochastic processes is proposed. Pitting corrosion can be considered as a combination of two physical processes: pit initiation process and pit growth process. The pit generation process is modeled as a non homogeneous Poisson process. The pit growth process is represented by a gamma process. A lifetime distribution model is derived based on the combined stochastic processes. Finally the proposed models are tested and simulated. The results indicate that the proposed model is feasible and valid for estimating the lifetime of port facilities.

Valuing hydrological forecasts for a pumped storage assisted hydro facility

Summary This paper estimates the value of a perfectly accurate short-term hydrological forecast to the operator of a hydro electricity generating facility which can sell its power at time varying but predictable prices. The expected value of a less accurate forecast will be smaller. We assume a simple random model for water inflows and that the costs of operating the facility, including water charges, will be the same whether or not its operator has inflow forecasts. Thus, the improvement in value from better hydrological prediction results from the increased ability of the forecast using facility to sell its power at high prices. The value of the forecast is therefore the difference between the sales of a facility operated over some time horizon with a perfect forecast, and the sales of a similar facility operated over the same time horizon with similar water inflows which, though governed by the same random model, cannot be forecast. This paper shows that the value of the forecast is an increasing function of the inflow process variance and quantifies how much the value of this perfect forecast increases with the variance of the water inflow process. Because the lifetime of hydroelectric facilities is long, the small increase observed here can lead to an increase in the profitability of hydropower investments.

A Study on the Nondestructive Evaluation of Material Degradation

The mechanical properties of in-service facilities under harsh environment a decrease as materials of the facilities degrade. This decrease of mechanical properties can affect the safety operation of the facilities. Therefore, the extent of degradation due to prolonged service exposure must be estimated. Nondestructive evaluation method is a good technique for monitoring the change of mechanical properties of in-service facilities. The most widely used nondestructive methods are the ultrasonic method and the indentation test, which is advantageous with respect of applicability to in-service facilities. The modified theoretical Vary's equation, considering nonlinear response due to material degradation, was proposed for obtaining the correlations between ultrasonic parameters and fracture toughness. Experimental results showed that ultrasonic attenuation, velocity, and nonlinear parameters have significant correlation with fracture toughness and yield strength. The nondestructive evaluation system can be used to obtain the yield strength and ultrasonic parameters simultaneously, and this information can be used to predict the fracture toughness. The predicted results produced good correlations with the experimental results, indicating that the nondestructive evaluation system can be effective in evaluating material properties and degradation, and the life time of facilities.